Fig. 3.

Selected IH protocols reported to elicit beneficial (potentially) therapeutic effects. Each protocol depicts the effective IH “dose,” including the severity of hypoxia during each episode (inspired O₂), the duration of hypoxic episodes (6 s to 12 h), the number of cycles per day (c/day), and the total time of exposure. Moderate IH protocols consisting of 9–16% O₂ and up to 15 cycles per day elicit beneficial effects in multiple physiological systems (blue shading in Fig. 1).